At present, the cigarette packaging film (cigarette film for short) used by domestic cigarette production enterprises is generally a biaxially-oriented polypropylene film (BOPP film for short). Because the BOPP film has high transparency, cigarettes packaged by the BOPP film are stiff and smooth, noble and doubled in price; and because the BOPP film has low price and moderate cost, the BOPP film is applied on a large scale in the cigarette production enterprises.
However, the conventional BOPP film has many defects in long-term use:
(1) because the BOPP film has poor blocking performance and the moisture penetrability thereof reaches 2.0 g/m2·24H, the BOPP film affects moisture protection of cigarettes. The cigarette product has high requirement for the moisture protection, because mildew caused by moisture is quickly grown to produce peculiar smell of the cigarettes, and customers can distinguish it upon smoking and certainly require for returning. Warehouses of cigarette plants and tobacco companies have extremely good moisture-proof performance, and big boxes of cigarettes stored in the warehouses with extremely good sealing property are not moisturized; but retail stores have no special warehouses, and cigarette packages stored in simple storage containers such as iron boxes and the like are easily moisturized and mildewed due to long retail period, much rainwater and moist climate in the south, so great loss is brought to the enterprises.
(2) with rapid development of cigarette machinery, more and more full-automatic high-speed packaging machines are introduced, and the packaging speed of the cigarettes is quicker and quicker, so the requirement for the cigarette film is higher and higher. The conventional cigarette film using the old-fashioned packaging machinery is not smooth in packaging, for the high-speed packaging machines have higher requirements for slip property, anti-blocking property, toughness and the like of the film. Therefore, the film must be improved on structure, process and formula to meet the requirements of the high-speed packaging machines.
(3) the packaging expense is a costly expenditure in the cigarette industry. Under the equivalent degree of the packaging quality, packages should be lightened to respond energy conservation and emission reduction raised by the government, so the improvement on the cigarette film is urgent.
(4) the cigarette industry has fat profits, the events that lawbreakers produce fake cigarettes to obtain high profits by infringing brands emerge endlessly, and the customers have poor identification ability on the cigarettes, so the anti-counterfeiting work on cigarette packages must be enhanced.
Aiming at the condition that the conventional cigarette packaging film cannot adapt to the development, the cigarette packaging film is required to be improved to meet the requirement of “low carbon” economy so as to meet the development requirement of the tobacco industry.